基于星历辅助的导航星座星间链路捕获初始信息求解算法

摘要

针对星间链路信号动态范围大、捕获时间要求短之间的矛盾，提出了一种捕获初始信息的求解算法。该算法基于导航星座的星历资源和动态特性，采用迭代的方法对信号传输时延和多普勒频率进行估计。分析指出，该算法实现过程简单，收敛速度快，估计精度高，两次迭代即可实现时延估计精度达到纳秒级，大大降低了捕获实现的难度和复杂度，适合星上资源要求比较严格的场合。分析基于北斗导航星座模型展开，对我国北斗导航星间链路的设计提供了参考。%In view of the large dynamic and fast acquisition requirement of inter-satellite links (ISLs)signal,a capture initial information solution method is presented for ISLs of navigation constellation.This method evaluates time-delay and Doppler frequency based on ephemeris.The analysis shows that this method has a simple realization process,a high speed of restraining and a high precision of evaluation,and can achieve the degree of nanosecond for the time delay through merely two times of iteration,which has greatly reduced the computing difficulty and complexity. This analysis is made upon the model of BeiDou navigation system and can provide reference for our country’s ISLs design.